Container closure having pull-tab opening means



Feb. l8, 1969 I J. F. SCHARF ETAL 3,428,211 CONTAINER CLOSURE Filed Oct.24, 1966 Sheet r 2 VENTOR M wauomvf zi aun s w'msows. Porrs 5 I 20yw-vmv F. saw/42F ZMLM .JMW 244$ I Palm-18, 1969 F, scH ETAL 7 3,428,211

CONTAINER CLOSURE v Filed Oct. 24, 1966 7 "Sheet 2 of 2 INVENTORS W144IIMJ. A.- 019R IIIVJ'OIVS. Pa 7' r5 BY Ja /rev F. sax/Aw;

United States Patent 12 Claims ABSTRACT OF THE DISCLOSURE A containerclosure having a tear strip opener wherein the removable panel which isdefined by a primary score line includes a secondary score line and apull tab which is secured to the removable panel at the collar portionformed by the primary and secondary score lines. The pull tab extendstransversely with respect to the primary and secondary score lines and alifting of the free end of the tab will rupture the secondary score lineand initiate rupture of the primary score line and twist the collarportion to facilitate subsequent rupture of the primary score line.

This invention relates generally to container closures and moreparticularly to an improved closure having a tear strip opener.

Closures having a tear strip opener or a pull tab opener, as they arefrequently known, of the type contemplated by the instant invention areutilized to form an end wall of sealed containers or cans which arecommonly employed to contain liquid, semi-solid or flowable products.

Such closures having a tear strip opener generally comprise an end wallforming portion of a container, such as a conventional can, having agenerally planar surface provided with a line of weakness such as ascore line, defining an area of the end wall known as a tear strip,which is to be removed to form a dispensing opening. The tear strip orremovable area is provided with a small key or pull tab terminating atone end in a free end portion adapted to be gripped by the fingers of auser and at the opposite end in a fulcrum portion. Intermediate its freeand fulcrum end portions the pull tab is secured to the tear strip bysuitable means, such as by an integral rivetli-ke formation in the tearstrip which is mechanically interlocked about the defining edge of anaperture formed in the pull tab.' The pull tab thus forms a handle-likemember to be gripped by the user to effect rupture of the closurematerial along the score line and thereby sever the tear strip from theclosure wall to produce an opening in the end wall of the container orcan. While sealed containers provided with closures having such tearstrip openers have found increasing usage and have enjoyed considerablecommercial acceptance, several difficulties have been encountered intheir use by the ultimate consumer. Such difficulties have quitenaturally resulted in a reluctance among consumers to readily accept andemploy the tear strip opener rather than employing conventional canopening devices. Thus, a frequent source of annoyance and resultingconsumer aversion to tear strip openers has been the considerable forceand consequent effort necessary to cause both the initial and subsequentprogressive rupture of the closure material along the score line. Thenecessity of applying such considerable force to the pull tab in orderto effect initial and progressive rupture along the score line isundesirable not only because of the difliculty experienced by the userin opening the container but also because the pull tab will frequentlyseparate from the tear strip without elfecting desired rupture of theclosure material along the score line. Such unintentional separation ordetachment of the pull tab from the tear strip commonly occurs at thebeginning of the opening operation when the pull tab is lifted to effectinitial rupture along the score line and, of course, renders the tearstrip opener inoperative.

Moreover, prior art tear strip type closure constructions, particularlythose wherein the area of the tear strip constitues substantially theentire end wall of the closure, are frequently such that the dispositionof the portion of the tear strip severed by the initial lifting of thepull tab to initiate rupture of the score line is unfavorable for thesubsequent progressive rupture of the remaining intact portion of thescore line required to elfect complete severance of the tear strip fromthe closure. Thus, after initial rupture of the score line of such priorart tear strip closure constructions, user is frequently obliged toexert variously directed distorting forces upon the pull tab and tearstrip in order to effect complete rupture along the score and severanceof the tear strip from the closure. The imposition of such variouslydirected forces upon the pull tab and tear strip not only imposes aninconvenience upon the user, but also results in the imposition ofundesirable stresses upon the connection of the pull tab and tear stripas well as an undesirable deformation and contortion of the tear stripitself which can result in a rupture or breaking of the tear stripbefore it has been completely severed from the closure. Obviously, it istherefore desirable that a tear strip closure be such that the tearstrip can be completely severed and removed therefrom by simple naturalmovements of the user, such as by a lifting and pulling of the pull tab,which require only a minimum of eflort.

Furthermore, the greater the effort necessary to effect initial rupturealong the score line, the stronger and more rigid must be the pull taband its connection to the tear strip. Thus, reduction of the effortnecessary to effect initial rupture along the score line is alsoobviously desirable since the pull tab and the closure wall, from whichthe integral rivet-like tab connection means is formed, can be formed oflighter gauge, and thus less expensive, material.

Accordingly, it is a principal object of the present invention toprovide an improved closure having a tear strip opener.

Another object of the present invention is to provide an improvedcontainer closure having a tear strip opener which can be easily openedby the average person.

A still further object of the present invention is to provide animproved container closure having a tear strip opener wherein a minimumeifort is necessary to effect initial rupture of the preformed scoreline.

Another object of the present invention is to provide an improvedcontainer closure having a tear strip opener wherein the likelihood ofseparation of the pull tab from the tear strip during opening of theclosure is reduced.

Still another object of the present invention is to provide an improvedcontainer closure having a tear strip opener which can be easily openedby the average person by simple natural movements which require only aminimum of effort.

A further object of the present invention is to provide an improvedcontainer closure having a tear strip opener which can be readily openedby a simple lifting and pulling of a pull tab secured to the tear strip.

Another object of the present invention is to provide an improvedcontainer closure having a tear strip opener wherein severance of thetear strip is initiated by simply lifting a pull tab secured thereto andthe initially severed portion of the tear strip is disposed so as tofacilitate the subsequent progressive rupture of the closure materialalong the remaining intact portion of the score line.

Other objects and the entire scope of the present invention will becomeapparent from the following detailed description and by reference to theaccompanying drawings. It should be understood, however, that thedetailed description and specific examples, while indicating preferredembodiments of the invention, are given by way of illustration only,'since various changes and modifications within the spirit and scope ofthe invention will become apparent as the description herein progresses.Reference is now being made to the accompanying drawings, which form apart hereof, wherein:

FIGURE 1 is a top plan view of a container closure having a tear stripopener embodying the present invention;

FIGURE 2 is a top plan view of the container closure shown in FIGURE 1before assembly of the pull tab thereto;

FIGURE 3 is a perspective view of the pull tab utilized on the closureshown in FIGURE 1;

FIGURE 4 is a sectional view taken along the line 44 of FIGURE 3;

FIGURE 5 is a sectional view taken along the line 5--5 of FIGURE 1;

FIGURE 6 is a top plan view of a container closure having a tear stripopener embodying the present invention with the tear strip partiallysevered from the closure;

FIGURE 7 is a sectional view taken along the line 7--7 of FIGURE 5;

FIGURE 8 is a fragmentary perspective view of the partially openedclosure shown in FIGURES 6 and 7;

FIGURE 9 is atop plan view of a modified form of the present invention;

FIGURE 10 is a top plan view illustrating another modified form of thepresent invention; and

FIGURE 11 is a top plan view illustrating still another modified form ofthe present invention.

Referring now to FIGURES 1, 2, 3, 4, and 5 of the drawings, there isshown a container closure 10 formed of a suitable material, preferablyan aluminum alloy, having a flexible, substantially flat or planar endwall forming portion 12 provided with a tear strip opener 14. The

flexible planar end wall 12 will be seen to be disc shaped,

and is adapted to form one end wall of cylindrical container or can 16of the type commonly employed in the marketing of liquid or semi-solidmaterials or other consumer products, such as frozen juices or the like.As is well known, the outer circular edge or rim of the closure 10 isprovided with an annular bead or flange 18 adapted to effect a sealedjuncture between the closure 10 and the cylindrical side wall of thecontainer 16 so as to form and end wall thereof.

The tear strip opener 14 comprises an elongated pull tab 20 having atransversely centered longitudinal axis AA and an opening pattern ortear strip 22 defined by an endless line of reduced metal thickness orprimary score line 24 formed in the planar disc-like end wall 12 of theclosure 10. As best seen in FIGURES 1 and 2, the primary score line 24is of a circular configuration and is formed closely adjacent theannular peripheral head 18 so that the tear strip 22 defined therebycomprises a removable disc-shaped area which constitutes substantiallythe entire end wall of the closure 10. Of course, as

will be evident hereinafter, the removable area of the closure Wallwhich is defined by the endless primary score line need not constitutethe entire end wall of the closure, but rather can constitute ony asegment thereof and can also be of any desired non-circularconfiguration.

The tear strip 22 also includes a secondary line of reduced metalthickness or score line 26 of limited extent formed radially inwardly ofthe endless primary score line 24. The secondary score line 26 will beseen to extend generally transversely with respect to the longitudinalaxis AA of the pull tab 20 and terminate in opposed terminal ends 28 and30, respectively, radially inwardly of the primary score line 24 so asto define a tear strip collar portion 32 therebetween. Preferably, thesecondary score line 26 has a slighty arcuate configuration, as bestseen in FIGURES 1 and 2, which is generally convex towards the collarportion 32. In addition, the secondary score line 26 can include adiscontinuity or interruption in the form of a relatively sharp rupturestress concentrating apex or junction 34 formed by angularlyintersecting portions of the secondary score line 26 intermediate theopposed ends 28 and 30 thereof. The relatively sharp score line junction34, which will be seen to be in vertical alignment with the longitudinalaxis AA of the pull tab 20, acts as a point of rupture stressconcentration to reduce the lifting effort which must be applied to thepull tab to initiate removal of the tear strip 22 from the closure 10,as will be described more fully hereinafter.

The pull tab 20, which is also preferably formed of a suitable metalsuch as aluminum, has a generally elongated configuration and incudes anenlarged free end handle portion 36 preferably in the form of ring 38adapted to be gripped by the fingers of a user, and a fixed end fulcrumportion 40. Preferably, the inner and outer edges of the ring 38 aresmooth and rounded so as to be free of any sharp edges which mightinflict injury on a user gripping the pull tab 20 during an openingoperation. The opposed fixed end fulcrum portion 40 terminates in aslightly arcuate end edge 42 which overlies a segment or portion of theprimary score line 24. In order to increase the rigidity of the fulcrumportion 40 as well as to facilitate initial rupture of the primary scoreline 24 by concentrating the rupture force applied to the tear strip 22through the pull tab 20 along a line or narrow area, the fulcrum portion40 is provided with a short longitudinally extending depressed bearingrib 44 as best seen in FIGURES 3 and 4. The rib 44, which can beconveniently formed by simply bending or slightly creasing the fulcrumportion 40 of the pull tab 20 on its longitudinal axis AA, provides arelatively narrow bearing surface which engages the underlying collarportion 32 of the tear strip when the free end portion 36 of the pulltab 20 is lifted.

In addition, the substantially straight longitudinally extending sideedges 46 and 48, which will be seen to converge as they extend from thefree end portion 36 to the fulcrum end portion 40 of the pull tab 20,can each be provided with a strengthening bead or rib 50 and 52,respectively. Such ribs 50 and 52 provide the pull tab 20 with addedrigidity so that it will effectively resist transverse bending duringopening of the closure, and can be conveniently formed by hemming orfolding the marginal edge portion edge of the tab inwardly upon itself.

At the fulcrum end 40 the pull tab 20 is provided with a suitableaperture 54, through which an integral rivetlike formation 56, formed inthe collar portion 32 of the tear strip 22 closely adjacent to thesecondary score line 26, extends to mechanically interlock and therebyoperatively secure the pull tabe 20 to the tear strip 22. As best seenin FIGURE 1, the pull tab 20 is disposed such that the longitudinal axisAA thereof extends radially with respect to both the primary score line24 and the secondary score line 26. In addition, as best seen in FIGURE5, the pull tab 20 will thus be face wisely engaged with the outersurface of the tear strip 22 and will not interfere with normal stackingof the containers 16 for shipment and display.

To remove the tear strip 22 and thereby create an opening in the closurefor the discharge of the container contents, the ring 38 at the free endportion 36 of the pull tab 20 is gripped and lifter or raised from theunderlying surface of the closure end wall 12. As the free end 36 of thepull tab 20 is lifted, the secondary score line 26 and the portion ofthe primary score line 24 adjacent the fulcrum portion 40 of the tabwill rupture and the collar portion 32 of the tear strip 22 definedthereby will twist sharply out of the plane of the end wall 12, as shownin FIGURES 6, 7, and 8. The sharp angle of entry of the severed collarportion 32 to which the pull tab 20 is secured permits the primary scoreline 24 to be progressively and completely ruptured to sever the tearstrip 22 from the closure 10 by simply pulling the tab away from theclosure 10.

The initial lifting of the free end portion 36 of the pull tab 20 causesan upwardly directed score line rupturing force to be applied throughthe integral rivet-like formation 56 to the portion of the collar 32adjacent the secondary score line 26 as the fulcrum portion 40simultaneously bears on, and applies a downwardly directed score linerupturing force to the portion of the collar 32 adjacent the outerprimary score line 24. The rupture of the inner secondary score line 26which occurs immediately before, or substantially simultaneously with,the initial rupture of the primary score line 24 reduces the effortnecessary to effect such initial rupture of the primary score line 24(as compared to the lifting effort which would be required to effectinitial rupture of the primary score line 24 if the secondary score linewere not provided) and assures optimum orientation of the initiallysevered portion of the tear strip 22 for effecting the completeseverance thereof from the closure 10 by simply pulling the pull tab 20away from the closure 10.

Referring now to FIGURE 9 of the drawings, there is shown a modifiedform of container closure 110 having a tear strip opener 114 embodyingthe present invention. The contruction of the tear strip opener 114 ofthe closure 110 differs from the tear strip opener 14 just described inthat the inboard or secondary score line 126 comprises a substantiallystraight line terminating in opposed terminal end portions 128 and 130radially inwardly of the primary peripheral score line 124. In addition,the secondary score line 126 does not include a stress concentratingapex intermediate its opposed end portions. The operation of the tearstrip opener 114 is however, substantially as previously described withreference to the tear strip opener 14.

Referring now to FIGURE 10 of the drawings, there is shown anothermodified form of a container closure 210 having a tear strip opener 214embodying the present invention. The construction of the tear stripopener 214 of the closure 210 differs from that of the tear strip opener14 previously described in that the secondary score line 226 is formedby two straight line portions which diverge as they extend away fromtheir apex or juncture at 234 adjacent the integral rivet-like formation256 toward the free end 236 of the pull tab 220 so as to be generallyconvex toward the collar portion 232.

Referring now to FIGURE 11 of the drawings, there is shown anothermodified form of a closure 310 having a tear strip opener 314 embodyingthe present invention. The construction of the tear strip opener 314 ofthe closure 310 differs from that of the tear strip opener 14 of theclosure 10 aforedescribed in that the endless primary score line 324 isof a non-circular configuration and the removable area or tear strip 322defined thereby constitutes only a segment of the closure end wall 312.The secondary score line 326 formed in the tear strip 322 issubstantially indentical to the secondary score line 26 previouslydescribed in connection with the tear strip opener 14, and terminates inopposed ends 328 and 330 inwardly of the periphery of the tear strip 322defined by the primary score line 324. As was the case with the otherembodiments of the invention previously described herein, the secondaryscore line 326 and the radially outwardly adjacent portion of theprimary score line 324 define a relatively narrow collar portion 332 towhich the fulcrum end 340 of the pull tab 320 (shown in broken lines) isattached by an integral rivet-like formation 356 formed in the tearstrip 322.

It will thus be seen that the objects of this invention have been fullyand effectively accomplished. It will be realized, however, that theforegoing specific embodiments have been shown and described only forthe purpose of illustrating the principles of this invention and aresubject to extensive change without departure from such principles.

What is claimed is:

1. A container closure having a peripheral bead for attaching theclosure to the end of a container; said closure further having aflexible generally planar disc surrounded by said peripheral bead andadapted to overlie the end of the container to which it is attached,said flexible disc having a first material thickness reducing scoredefining a predetermined opening pattern and a second material thicknessreducing score formed to lie radially inwardly of said first score todefine a collar between said scores; an opening tab including a fulcrumportion terminating adjacent said first score and a handle portion; andmeans securing said fulcrum portion to said collar at a point adjacentsaid second score to cause the axis of said tab to lie radially of bothscores; said score and tab arrangement responding to a lifting of thetab handle portion to fracture said second score and thereby permit saidcollar to twist out of the plane of said disc to permit a sharp angle ofentry as the fulcrum end of said tab fractures said first score, saidarrangement further permitting said first score to be fractured alongits entire length in response to a pull on the handle portion of saidta-b directed away from said closure.

2. The structure defined in claim 1 wherein at least a portion of thefirst score is formed adjacent the peripheral bead of the closure.

3. The structure defined in claim 1 wherein the second score is arcuateand generally convex toward the collar.

4. The structure defined in claim 3 wherein the second score includes arupture stress concentrating apex intermediate the terminal ends thereofwhich facilitates fracture of said second score.

5. The structure defined in claim 1 wherein the fulcrum portion of thetab includes a longitudinally extending narrow bearing surface whichengages the collar when the handle portion of said tab is lifted.

6. The structure defined in claim 1 wherein the second score is formedby two substantially straight score line portions intersecting adjacentthe means securing the tab to the collar.

7. The structure defined in claim 2 wherein the first score is of acircular configuration.

8. The structure defined in claim 2 wherein the first score is of anon-circular configuration.

9. A container closure having a tear strip opener in a fiat planarcontainer Wall forming portion thereof comprising in combination aprimary endless score line formed in said wall portion defining a tearstrip; a secondary score line formed in said tear strip and terminatingin terminal end portions spaced inwardly of said primary score line soas to define a collar portion between said primary and secondary scorelines; an elongated pull tab including a handle portion at one end and afulcrum portion at the other end; and means connecting and securing saidfulcrum portion of said pull tab to said collar adjacent said secondaryscore line so that the longitudinal axis of said pull tab extendstransversely with respect to said secondary score line and the terminalend of said fulcrum portion of the pull tab is disposed adjacent aportion of said primary score line whereby lifting of the handle portionof said pull tab will effect rupture of said secondary score line,initiate rupture of said primary score line and twist the collar portionout of the plane of said wall so as to facilitate the subsequentprogressive rupture of said primary score line to sever said tear stripfrom said wall and thereby produce an opening in said closure.

10. The structure defined in claim 9 wherein the primary score line isof a circular configuration.

11. The structure defined in claim 9 wherein the secondary score linehas an arcuate configuration convex toward the collar portion.

12. The structure defined in claim 9 wherein the terminal end of thefulcrum portion of the pull tab includes a relatively narrow bearing ribwhich is adapted to engage the underlying collar portion of the tearstrip when the handle portion of the pull tab is lifted.

References Cited UNITED STATES PATENTS 3,301,432 1/1967 Novak 22O543,322,296 5/1967 Khoury 22048 3,326,406 6/1967 Brown 22054 3,338,4638/1967 Henricksori 22054 THERON E. CONDON, Primary Examiner.

G. T. HALL, Assistant Examiner.

